Posted
by
Zonk
on Friday February 02, 2007 @04:28PM
from the look-for-mon-cal-first dept.

ZonkerWilliam writes "It seems, at least theoretically, that there may be 'ocean planets' out there in the galaxy. If there are, we are closer than ever to detecting them. The formation of such planets is fairly likely, reports the PhysOrg article, despite the lack of an obvious example in our own solar system. We may have a former ocean planetoid in the neighborhood, orbiting the planet Jupiter: the moon Europa. These water worlds are the result of system formation castoffs, gas giant wannabes that never grew large enough. If any of these intriguing object exist nearby, the recently launched CoRoT satellite will be the device we use to see it. The article explains some of the science behind 'ocean worlds', as well as the new technology we'll use to find them."

You really have to feel sorry for poor Quayle. He was (*is*) actually an intelligent fellow. He just can't speak in public to save his life.

In this particular speech, he meant to say that where there's water, there's oxygen to be extracted. In this, he's quite correct. It would take a significant amount of energy, but it's perfectly feasible to extract breathable oxygen from water on Mars.

You really have to feel sorry for poor Quayle. He was (*is*) actually an intelligent fellow.

MOUSEBENDER: It's not much of a cheese shop, is it?WENSLEYDALE: Finest in the district, sir.MOUSEBENDER: Explain the logic underlying that conclusion, please.WENSLEYDALE: Well, it's so clean, sir.MOUSEBENDER: It's certainly uncontaminated by cheese.

Full qoute: "Mars is essentially in the same orbit... Mars is somewhat the same distance from the Sun, which is very important. We have seen pictures where there are canals, we believe, and water. If there is water, that means there is oxygen. If oxygen, that means we can breathe."

In this particular speech, he meant to say that where there's water, there's oxygen to be extracted.

Really? The part about canals strongly indicates he had no clue what he was talking about. He linked the water to canals, and

Pretty much. The more Mr. Quayle spoke, the more nervous he got, and the worse his mistakes got. It's interesting to watch, because he knows he's not making any sense, but his attempts to make it better just make it worse.In Quayle-ese:

Same Orbit == "Similar enough to be semi-hospitable to human life."Canals == "Channels through which water once flowed."

At least he didn't have to speak on the possibility of microbial life on Mars. It would have been War of the Worlds all over again!

I really hope they don't find any of them. If they do, we'll have hundreds of water world remakes and the level of pain that would bring is too much to bare.

What's worse is when you think about how amazingly vaste the entire universe is: It's entirely possible that there's a planet out there where, through sheer chance, the events of Waterworld actually took place-- whoah, I need to lie down for a sec.

I know it's a nitpick, but of course we're closer than ever to detecting them. Guess what, we're closer to detecting them now than when you began reading this reply (by a couple seconds, but still closer).

Unless someone's already found them. In which case we're further from finding them now than we have been since as long before they were found as we are past when they were found now. Yeah. That parses well.Of course, this all assumes that the terms "closer" and "further" are being used to measure a temporal distance. If I'm looking for my keys, I could have been closest (physically) to finding them this morning when I was in the kitchen where they're under the newspaper, even though in only a few minute

I know it's a nitpick, but of course we're closer than ever to detecting them. Guess what, we're closer to detecting them now than when you began reading this reply (by a couple seconds, but still closer).

You're older than you've ever been.And now you're even older.And now you're even older.And now you're even older.

I'm pretty sure we already have plenty of experience surviving on an ocean world, since we already live on one. What we're not used to is surviving while sea levels rise, perhaps uncontrollably, which is probably what you meant.

The projected maximum rise in sea level due to total melting of glaciers is around 80m. [usgs.gov] The average elevation of exposed land is about 2870m, [ilstu.edu] which is about 35 times as high. Melting everything won't inundate the globe, but it will require relocation from low-lying areas.

If you read the article, an ocean world is entirely water with a frozen core of water. Earth has a crust over a molten core that's cover with two-thirds of water. Technically, Earth is not an ocean planet. Assuming that you don't include the 40 days and 40 nights when God flooded the earth back in the days when building an ark on dry land was considered a stupid idea.

The Earth is a very large lump of iron and rock with just enough water for a few puddles to thinly cover 2/3 of its surface. The article is talking about whole planets composed almost entirely of water. Think of a bunch of melted comets that got smooshed together.

Minor nitpick, but by volume Earth is mostly Silicon, and by mass it's almost half oxygen. (Silicon makes up another quarter of the Earth's mass total mass).Earth is called a "water world" because it has a hydrosphere, though. The presence of water on a planet is by no means unique (Europa, Mars, most of the asteroids in our solar system), but the presence of water in abundance in the star's green zone hasn't been seen anywhere else. Earth is the only planet in the solar system where the *surface* temperatu

Just after writing this I actually RTFA and felt a bit stupid. I had wondered why more commenters had picked up on the whole "Earth" thing. Judging from the fact my comment got modded up (so far, anyway), it goes to show some of the moderators don't RTFA either.

Interestingly, any truly "Earthlike" planets we find ARE more likely to be covered in water. We have oceans here on Earth only because we also have continents. While the exact origins of the continents are still debated, the one common theory is that they're remnants of the same impact that formed the moon e.g. the impact blew off much of the surface of the original Earth, and that our "continents" were formed from the portion of the original crust that wasn't destroyed. Since the new crust was formed from denser materials deeper in the planets core, the lighter original crust rode higher on the mantle than the rest of it. That original crust cracked apart, became the foundations (cratons) for the continents we have today...or at least kicked off a cycle of crustal formation that lead to the continents we have today. Comparable planets in our Solar System that did not experience similar impacts (Mars and Venus) have relatively flat surfaces and nothing resembling continents.

What if that impact had never occurred? The Earths surface would be level, like the other terrestrial planets, and instead of the water settling into the lower basins (the oceans), it would cover the entire surface of the planet to a depth of several kilometers. Only a few of today's highest peaks would extend above that water level. Those peaks, in all likelihood, wouldn't exist either. Not only would the tectonics needed for their formation be absent, but a world without continents would have monster surface waves and erosion would scrub them below the waterline in a few million years. If there were ANY life here, it would be no more advanced than the fish which exist today.

Unfortunately, if we DO ever get out into space and find "Earth-like" planets of comparable mass and temperature, they will probably be water-bound just as the Earth would have been.

Actually, the Earths convective mantle may be a byproduct of its plate tectonics, and not the other way around. Venus provides us with an excellent example of this, as it is in many ways a geologic twin of the Earth...minus the impact and big moon. Venus has a molten core and geologic activity (it's covered in volcanoes), but no tectonics. Why? Because there is no convection in the mantle. That's also why Venus has no magnetic field. The creation of a dynamo for an electric field requires a metal conductive core, rotation, and convection in the mantle. Magnetic analysis of the planet indicates that it has a conductive metal core, and its rotation, while slow, is sufficient to generate a field of some intensity.

So why no magnetic field? No convection. Why no convection? Two possibilities. 1) The lack of tidal stresses from a comparatively large moon permitted its mantle to largely solidify already, as happened on Mars. 2) On the other hand, the LACK of tectonics may have deprived the core of a way to vent excess heat. Convection happens on Earth because the top of the mantle is cooler than the bottom, and the top is cooler BECAUSE it can let off heat through tectonics. It's a self perpetuating process. With Venus, the lack of tectonics deprived the mantle of any heat release sources other than volcanism. This would permit the Venusian mantle to get much hotter than the mantle on our own planet. The increased heat without outlet would lead to a mantle far more uniform in temperature...and a mantle that is uniformly hot will have no convection.

So it becomes a self-perpetuating cycle. Something fractured the early crust of our planet, permitting subduction. Subduction and tectonics in general introduced temperature irregularities into our mantle, which kicked off convection. Convection then drove tectonic activities by itself.

A protoplanet under bombardment would have a fairly consistent mantle temperature once bombardment began to ease. Energy imparted from impacts would spread throughout the body, and cooling would occur uniformly at the outer edges of the planet where the molten material came into contact with space. The planet would then begin cooling from the outside in, resulting in a relatively uniform crust. Again, you merely need to look at all of the other terrestrial bodies in our own solar system to confirm the model.

It appears that something "else" is required to kickstart plate tectonics. The only really major thing we can identify, that fits the models, is our moon. The giant impactor which blasted lunar material away from the Earth disrupted the mantles temperature and blasted away a signifigant portion of the lighter material which should have formed our crust. The glancing blow which the models suggest would have been required for the Giant Impactor theory would have also left the side of the planet opposite the impact relatively unscathed (aside from the many millenia of debris impacts which certainly followed). As an added bonus, the newly formed moon around the planet, comparatively large and in a tight orbit, would have induced tidal forces which helped (and still help today) to keep the mantle moving.

No impact = No giant moon, no disruption of the even cooling of the surface, no disruption of the mantle, no convection, and no tectonics. Geologically, the Earth would be Venus, only covered in 1-2 kilometers of water and with a more temperate atmospheric blanket (it would probably be a far colder planet than it is today). Aside from a volcanic island or two, the planet would be a big orbiting ball of water.

The planet's core is a giant RTG [wikipedia.org]. Most heavy materials like iron, nickel, and the radioactive metals are in the core. The longer lived radioactives like U-238 continue to decay and heat the core to this day. Mind you, I'm talking about decay not chain-reaction fissioning. While "natural reactors" are possible that isn't what is happening here.

Ok, thanks. So, the GGP is not quite right saying "it is a self-perpetuating process". Tectonic movements simply carry the RTG-produced heat to the surface — and our perpetuated by the decay, not by "self"...

'If there were ANY life here, it would be no more advanced than the fish which exist today.'That conclusion doesn't follow anything else you've said. Is there some reason you feel that being a land-dweller is prerequisite to being an advanced lifeform? I wouldn't even consider it a safe assumption that land dwelling creatures on earth (including man) are the most advanced to have evolved on our own planet. Unless of course you define 'advanced' strictly on the basis of tool usage and not on the basis of int

What if that impact had never occurred? The Earths surface would be level, like the other terrestrial planets, and instead of the water settling into the lower basins (the oceans), it would cover the entire surface of the planet to a depth of several kilometers. Only a few of today's highest peaks would extend above that water level. Those peaks, in all likelihood, wouldn't exist either. Not only would the tectonics needed for their formation be absent, but a world without continents would have monster surf

Before the Voyager got to Uranus and Neptune, Dr. Russ Humphreys proposed that the plants were originally made of water, and made very accurate predictions of their magnetic fields based upon that theory.

The field would decrease exponentially, that is, by a fixed percentage per unit time (Figure 3) . (Since readers of this Quarterly come from very diverse areas of science, I am italicizing and explaining the more technical terms).

Thought this was funny. I have to start doing this on Slashdot as well, since only scientists specializing in astronomy and evolutionism know the meaning of words like "exponentially".

I was trying to explain this theory about fifteen years ago to an x-girlfriend.
The way I thought about it was:
Heat(scale? strength?)of Star vs Mass of Planet vs Distance from Star
I called it the God Ratio in a tongue-in-cheek sort of way.
I have no idea what calculations I was playing with and was way off of any "real" science about it, but the basic gist is the same.

OK, now that I've RTFA it's not quite the same thing. My "God Ratio" was talking more about life on other planets. More precisely, the "God Ratio" dealt with planets with polar ice caps. The polar caps, imho are a necessary part of a stable planet.

I thought you might be talking about the idea of Galactic Habitable Zones [astrobio.net] (which deals with characteristics of our solar system as well.) But it sounds more like you might be thinking of the Rare Earth Hypothesis [wikipedia.org] which focuses more on the planet and the solar system they reside in. While there is a good deal of consideration given to glaciation, it focuses more on it's possible impact on evolution. It's a wonderfully interesting book, if you haven't read it. It also gives an equation based on the Drake equa

Rare Earth Hypothesis is definitely what I was getting at, though I wouldn't have known it back then. Where was Wikipedia 15 years ago, huh?
I could be happily married right now, but to a different woman(I am happily married)!
It's funny in a way, in that her basic premise, which prompted my theory, was basically the Fermi paradox. "If there are intelligent beings from other worlds, we would know by now, we'd have proof..."
My answer to that was my own version of the REH, which I'd never heard of; but wo

If you'd like simulate a water world yourself, the EdGCM [columbia.edu] project has wrapped a NASA global climate model (GCM) in a GUI (OS X and Win). You can add CO2 or turn the sun down by a few percent all with a checkbox and a slider. Supercomputers and advanced FORTRAN programmers are no longer necessary to run your own GCM.

It is a very general GCM so included in the download are paleo-earth configurations. You can run a simulation of the earth from 750 million years ago [columbia.edu] when it was mostly covered in water (but also very cold) to see one possible scenario. As mentioned above, you can add CO2 and turn up or down the sun or any other GHG to see other scenarios.

Corot sounds like another space based IR telescope with an incrementally better mechanism to reject glare. The output is going to be an intensity graph over time, with small dips from planetary transits, the same thing we've been doing for many years.

The real breakthrough is when we finally have enough magnification and resolving power to see living things on other planets. The great barrier reef is a living thing that can be resolved from beyond Mars orbit with today's technology. The first extrasolar life we see is going to be something like a great barrier reef.

The trick is going to be making a telescope the size of the solar system. The mission is probably going to use 2 Hubble size telescopes on opposite sides of Mars orbit, with incredible magnification well beyond the diffraction limit of each telescope, and the highly diffracted images from both telescopes being combined in software to produce a corrected image with a virtual aperture the size of Mars orbit. Only with that kind of mission are you going to "detect" habitable, extrasolar planets.

Using optical interferometry to produce actual synthetic aperture images is turning out to be extremely difficult even with earth-based observatories with fiber-optic links between them. While ssing multiple telescopes in orbit like you suggest may be theoretically possible, but I'm seriously wondering about whether it'll be doable within any kind of foreseeable future. It's also going to take more than just two to produce actual images.A less technologically insurmountable potential way of getting extra-so

When I hear talk of ocean worlds I am always reminded of the amazing speculation about them that Stapledon did in his books.

In Olaf Stapledon's book "Star Maker" [wikipedia.org] (see here [sfsite.com] also) he describes one water world.. I'm thinking of the world of the living ships, not the that of the dolphin-crab symbionts or the avians. Living ship-like beings, think a cross between a whale and a squid with natural deployable sails. The symbionts eventually develop technology and starships because there are a few islands that bec

If were're talking about H20 I just can't see how there could be a core of ice. Core of rock sure, maybe ancoring down some ice but I don't see how a core could be mostly ice. The ice would immediately try to float to the surface.

These things have to weigh less than 10 times what the Earth weighs, or they will become gas giants. Our sun weighs 332,946 times as much as the Earth. Only objects weighing at least three times as much as our Sun can turn into black holes. Only a black hole can suck as hard as Water World. Therefore, these water planets are nothing like Water World.

Mass. Sorry, I meant "masses," not "weighs." Mass effects gravity, gravity effects orbits and such, we can tell from that. Don't ask me how, IANAAstrophysicist, but I do trust them to calculate this stuff correctly.

If you know how far away you are from an object and how quickly you're orbiting it (assuming your orbit is roughly circular) you can use simple algebra to get a rough idea of its mass.

Acceleration due to gravity is calculated as follows:

a = G * (m / r^2)...where a is the accelelration, G is the gravitational constant, and r is the distance between your two objects. Note that we're ignoring the acceleration of the sun toward the earth, which isn't technically correct, but this answer will be close enough.

Since we're looking for the Sun's mass, we solve this equation for m.

m = (a * r^2) / G

The first thing we need to figure out is the value of a, or how fast things accelerate toward the sun. The earth is 1.5e11 meters from the sun, and travels in a (roughly) circular orbit once every 365.25 days (or 3.16e7 seconds). If you calculate the circumferance of the earth's orbit given the radius, you get 9.42e11 meters. The earth is moving at roughly 2.98e4 meters per second.

The next step is to figure out how far the earth falls toward the sun every second. We can do this (again, roughly) without using calculus. Let's say that, for one second, the earth continues to travel in a straight line instead of a circle. If you subtract the earth's real orbital radius from this hypothetical one, you end up with the number of meters that earth falls every second, or a. Note that this isn't an exact calculation -- I would need to use calculus to do that -- but it's still "close enough". I'm an engineer, not a scientist, so be happy I used 3.14 for pi, as opposed to "about 3.":)

The earth's new distance from the sun, if it travelled at a tangent for sone second, would be calculated using the Pythagorean Theorum, as follows:

Subtracting the original distance from the sun, the earth has fallen about 2.96 millimeters in one second, which means that the earth is accelerating toward the sun at.00592 m/s. That's a. Now we just plug all that into the original equation:

Interesting, just looking at your first equation for acceleration, if I was to sit at one end of the bar drinking beer it would take me only 4273 and a half years to end up next to the cute blond at the other end of the bar, if we don't take into account her acceleration towards me, friction and all the other people sitting in between.

I know you were just making a joke... but objects of any size can become black holes, including individual protons.

No, he's referring to the Tolman-Oppenheimer-Volkoff limit - a neutron star above 3 solar masses will collapse to a black hole (or possibly a quark star), similar to Chandrasekhar's limit (about 1.44 solar masses) for forming a white dwarf. (Although because large stars blow off matter as they go through the changes, the starting mass for the star has to be better than about 8 solar masses.)

A proton couldn't become a black hole, its Schwarzschild radius is far less than a Planck length. It's generally considered that the smallest mass that can become a black hole (radius equal to the Planck length) is about 21.77 micrograms, called the Planck mass.